2016 RVHS H2 Biology Prelims Paper 2 Questions

River Valley High School Pg 1 of 23 Year 6 H2 Biology 9648 Paper 2 2016 Preliminary Examination II RIVER VALLEY HIGH SCHOOL YEAR 6 PRELIMINARY EXAMINATION II CANDIDATE NAME CENTRE NUMBER S INDEX NUMBER H2 BIOLOGY 9648/02 Paper 2 Core Paper 15 Sep 2016 2 hours Additional Materials: Answer Paper READ THESE INSTRUCTIONS FIRST Write your index number and name on all the work you hand in. Write in dark blue or black pen. You may use a HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Section A Answer all questions in the spaces provided on the question paper. Section B Answer any one question on the answer paper provided. Circle the question attempted on the cover page. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Section A 1 / 10 2 / 10 3 / 9 4 / 10 5 / 10 6 / 11 7 / 10 8 / 10 Section B 9 or 10* / 20 Total / 100 _____________________________________________________________________ This Question Paper consists of 23 printed pages.

River Valley High School Pg 2 of 23 Year 6 H2 Biology 9648 Paper 2 2016 Preliminary Examination II Section A (80 marks) Answer all the questions in this section. 1 Fig. 1.1 shows electronmicrographs of a zebrafish cell undergoing mitotic cell division. Fig. 1.1 (a) Explain the significance of mitosis to the development of zebrafish. [2] (b) (i) Identify stage A. [1] (ii) With reference to Fig. 1.1, describe two visible features that support the identification in 1(b)(i). [2]

River Valley High School Pg 3 of 23 Year 6 H2 Biology 9648 Paper 2 2016 Preliminary Examination II (iii) Explain the significance of stage D to cell division. [2] (c) Explain why sister chromatids are genetically identical. [3] [Total: 10]

River Valley High School Pg 4 of 23 Year 6 H2 Biology 9648 Paper 2 2016 Preliminary Examination II 2 Human Immunodeficiency Virus (HIV) is a retrovirus which infects immune cells expressing CD4 receptor on its cell surface membrane. (a) Explain the term retrovirus. [2] In 2012, the United States Food and Drug Administration (FDA) approved the OraQuick In -Home HIV Test, which is th e first test kit which can be b ought at pharmacies. The test kit relies on the presence of antibodies against gp120 in blood. Antibodies are produced by immune cells in response to exposure to forei gn particles. If an individual had been infected by HIV for at leas